07-18-2011 03:20 PM
My sister dropped her T410 and cracked the LCD screen, which clearly was not covered under the basic warranty. The $950 quote for repair was a little steep (basically the cost of the laptop) so we decided to try a repair ourselves. I replaced the LCD screen with a model suggested by the Lenovo rep. With the new screen in place, the backlight doesn't function at all (can see information on the screen with a flashlight but otherwise nothing). I also put the old screen back in (which previously was backlit despite being cracked) and observed the same problem. I made sure the LCD cable was seated firmly at both ends.
Considering things as they stand now, my question is about the best route to take from here. As I understand it, since the LED backlight is powered by the system board, we either buy a new system board or use this laptop as a "desktop" attached to a standalone monitor. Replacing the LED sub card seems questionable for this particular problem (saw another post here with that conclusion). We could replace the LCD cable, but it seems to me more likely that the fuse on the motherboard is blown. If it comes down to motherboard vs. desktop use, we'll probably avoid the motherboard replacement since it is somewhat expensive.
Am I missing any obvious ideas? Should I consider replacing the LCD cable more seriously? Is the LED sub card more relevant to the LCD/backlight than I think? I'm hoping to get some confirmation on my understanding of the problem as well as any other possible solutions to help make a good decision about how to proceed.
Thanks for your help!
07-18-2011 11:39 PM
spencerkellis wrote:Is the LED sub card more relevant to the LCD/backlight than I think?
Yes, the backlight is LED. What else would that card be for? You should also make sure that the cable to that card is seated all the way, from what you describe it sounds like it came loose.
07-19-2011 02:00 PM
Thanks for the response! Those are good suggestions, and I have a couple clarifying thoughts and questions below:
I am aware the screen is LED-backlit, but I'm still not convinced the LED sub card is related to the backlight. The LCD cable directly connects the system board and the screen, and is the only active electrical connection to the LCD as far as I can tell. I've also seen a couple references to a fuse on the system board that is part of the circuit powering the LED backlight. On the other hand, the LED sub card has the activity LEDs and also appears to be connected to the integrated camera but I don't see any direct connections from the LED sub card to the LCD screen. These are the reasons why I'm curious whether the LED sub card is relevant - at first glance it appears associated by name and location, but the more I look into it the more it seems unrelated. (But, I'm asking because I don't know the system and could just be missing something).
This does seem like a problem easily caused by a poor connection, but I did check the LCD cable and it is firmly connected at both ends. At the motherboard end it appears to be held in place quite firmly by a screw and small plate. At the screen end, I made sure the cable was fully in place and secured with the tape. Also, when I shine a flashlight to see what's on the screen it doesn't appear distorted in any way like I might expect with a poor connection - just no backlight.
I'm not sure if it makes much difference for the current discussion, but this is the link to the model/instructions I've been using: http://www-307.ibm.com/pc/support/site.wss/document.do?sitestyle=lenovo&lndocid=MIGR-74568
Thanks again for the help.
07-19-2011 04:29 PM - edited 07-19-2011 04:35 PM
Fru# 63Y2121 - LED sub card 14.1-inch WXGA LED-backlight (1280x800) LCD service parts - ThinkPad T410, T410i - All Models 14.1-inch WXGA+ LED-backlight LCD service parts - ThinkPad T410, T410i - All Models
The site I pulled that from botched the description, I found a picture of the card and it does have the 3 LEDs for the bezel status lights on it. Did you leave the battery in the system or the power cable plugged in when you replaced the LCD? That is the only thing I can think of that would have blown the fuse. You should also discharge the system by holding down the power button for 10 seconds or so after removing the power cable and battery.
07-20-2011 04:36 PM
Yes, those are good thoughts. I did take out the battery while working on the system, but I did not hold down the power button to discharge stray capacitance - I'll definitely include that in future repair work.
So in terms of where to go from here, I think my original assessment is probably correct: I don't think it will be useful to replace the LED sub card; the cable is an unlikely culprit since there is no distortion of the picture on screen; and the only part left is the fuse on the system board.
Thank you again for thinking through the issue with me. If you (or anybody else) have any other thoughts I'm definitely open to them, but otherwise I'll probably move forward with this information.
09-19-2011 08:47 AM
10-26-2011 08:32 AM
I have the same problem.
Change my lcd, first crash and buy another with better definition but its so dark, it works but i cant see.
My old has this number of part LTN141BT09 and new LTN141AT15
Thanks in advance!
01-05-2012 04:32 PM
Usually, these symptoms indicate a blown fuse on the motherboard. The issue comes up frequently when LED-backlight screens are broken. Lenovo does not do this type of repair (other than motherboard replacement) It can be done, but most places do not have the specialized equipment to diagnose and repair.
11-25-2015 09:01 AM
if this is the motherboard problem mean as you say a fuse problem can you explain or guid me where is that fuse near or arround the connector of lcd strip or where or you have any picture.